Light combining devices are known in the art. US 2014/0240677, for instance, describes a light source comprising a light combining device for guiding incident light from a first light emitting source and incident light from a second light emitting source with different incident directions to combine two paths of incident light into one path of emission light emitted from a first optical path. The light combining device comprises a guide part, for guiding light from the second light emitting source to converge into the first optical path, and hindering a part of light from the first light emitting source from entering the first optical path, the luminous flux of the hindered part of the light being less than the luminous flux of light from the first light emitting source entering the first optical path. This light source can effectively reduce the cost and achieve a better heat dissipation effect and is especially suitable for a projection device.
WO2007/082021A2 discloses an optical manifold for combining a plurality of blue LEDs outputs to illuminate a phosphor for a single, substantially homogeneous output for white light. Two blue LEDs feed each a respective compound parabolic concentrator, and the blue light is converted by a green and yellow phosphor, respectively. The converted light is fed to two respective angle-rotator pair that feed an output mixing rod. Light of a red LED is mixed with the light from the two phosphors.
WO2015/113979A1 discloses a light emitting device comprising a first light source, a light guide made of a luminescent material and comprising a light input surface and a light exit surface wherein the light guide is adapted for receiving light from the first light and converting at least a part of the first light to second light, guiding the second light to the light exit surface and coupling the second light out of the light exit surface. The light emitting device further comprises a phosphor element arranged adjacent to a further surface of the light guide and a reflective element arranged adjacent the phosphor element. The phosphor element is adapted for converting light incident from the light guide to third light, and the light guide is furthermore adapted for receiving the third light, guiding the third light to the light exit surface and coupling the third light out of the light exit surface.
WO2016/162233A1 discloses a lighting device configured to generate lighting device light, wherein the lighting device light includes an emission band in the visible part of the spectrum which represents at least 80% of the total power of the lighting device light in the visible part of the spectrum, wherein the emission band has a full width half maximum of at maximum 60 nm, and wherein the emission band has a peak maximum, wherein said emission band comprises luminescent material light, wherein the lighting device comprises a solid state-based light source, configured to generate light source light having a peak maximum, and a luminescent material, configured to convert at least part of the light source light into said luminescent material light.